A. Examine the production of several cytokines by normal, malignant and transformed human and murine keratinocytes. Specifically the synthesis, translocation, membrane insertion and secretion of two cytokines will be examined. These are ETAF (IL- 1-like activity) and KTGF (which has IL-2 activity). The control of secretion of these two cytokines by UVA, UVB, temperature elevation and LPS will be compared. It will be determine whether the epidermal cytokines are released coordinately or whether they are under separate control. The regulation of ETAF release by glucocorticosteroids (GCS) will be examined to determine where in the process of cytokine synthesis and release, the GCS function. ETAF (IL-1) and KTGF (IL-2) are assayed with D-10 and HT-2 responder helper T lymphocytes respectively. B. The production of cytokines by individuals with disorders of epidermal proliferation will be examined in vivo, in tissue slice (organ culture) and in tissue culture. The responsiveness of cytokine production to GCS, temperature elevation and ultraviolet light will be measured. C. The influence of cytokines derived from keratinocytes and lymphocytes on keratinocyte growth and differentiation will be examined using several different markers of differentiation including plasminogen activator, cross-linked envelope formation, the pattern of keratin synthesis and the presence of pemphigus vulgaris antigen. Cytokines will be isolated by means of HPLC using both a sizing column (TSK-125) and reversed phase chromatography (HI PORE RP 318). Cytokines will be isolated from normal and transformed keratinocytes as well as WeHi, a source of colony stimulating factor (IL-3). D. Lymphocytes enter the epidermis in many disorders. The chemotactic effect of keratinocyte-conditioned media for helper and suppressor T-cells will be studied and using fractions purified by HPLC, the cytokine(s) responsible for chemotaxis will be identified. Chemotaxis by keratinocyte cytokines results in the appearance in the epidermis of lymphocytes the leading front analysis in micropore filter assays in Boyden chambers and time- lapse photography using sepharose beads impregnated with cytokines.